During the past week I have been practicing methods for merging a model, an idea, a concept, or a prototype, into a photograph of a real scenario or context. In our practice we use a SketchUp plug-in called Advanced Camera Tools that allows us to input very detailed information about a photograph like distance to the subject, height, focal length, and camera inclination to generate a precisely matched model view. It’s a great tool, but it takes some time and practice to get a successful result with it.
When this degree of accuracy is not required, however, SketchUp’s Match Photo feature comes in handy. It allows you to match the perspective of your model to a photograph, giving a reasonable impression of correct height, width, depth, and position in relation to each other when viewed from a particular vantage point. In order to experiment with this tool, I made an example of how three different types of awnings would look on our office building. The process of matching is fairly simple: you start by finding parallel lines in the photograph in order to locate perspective vanishing points. After that you scale the model to match the photograph. (For a clever play on visual dimensionality, check out this project about 2d chairs in the three-dimensional world.)
The trick with match photo is to make the model appear to be in similar perspective to the photograph. In the perspective chair example you can see the painted chairs in matching perspective with its context only from one point. With the awnings case, the position of the model is not necessarily the correct one compared with the photograph but you get the illusion of the object being in correct perspective once you adjust your perspective grid with the photograph.
Like anything, this tool has pros and cons: although it involves a very simple process, it’s impossible to create a match if the photograph does not have at least one pair of surfaces that are at right angle to each other. In this case, I was able to come up with some good results very quickly.